Conformationally supramolecular chirality prevails over configurational point chirality in side-chain liquid crystalline polymers.

In nature, the communication of primary amino acids in the polypeptides influences molecular-level packing, supramolecular chirality, and the resulting protein structures. In chiral side-chain liquid crystalline polymers (SCLCPs), however, the hierarchical chiral communication between supramolecular mesogens is still determined by the parent chiral source due to the intermolecular interactions. Herein, we present a novel strategy to enable the tunable chiral-to-chiral communication in azobenzene (Azo) SCLCPs, in which the chiroptical properties are not dominated by the configurational point chirality but by the conformationally supramolecular chirality that emerged. The communication of dyads biases supramolecular chirality with multiple packing preference, thereby overruling the configurational chirality of the stereocenter. The chiral communication mechanism between the side-chain mesogens is revealed through the systematic study of the chiral arrangement at the molecular level, including mesomorphic properties, stacking modes, chiroptical dynamics and further morphological dimensions.

Srgap2 suppression ameliorates retinal ganglion cell degeneration in mice.

Slit-Robo GTPase-activating protein 2 (SRGAP2) plays important roles in axon guidance, neuronal migration, synapse formation, and nerve regeneration. However, the role of SRGAP2 in neuroretinal degenerative disease remains unclear. In this study, we found that SRGAP2 protein was first expressed in the retina of normal mice at the embryonic stage and was mainly located in the mature retinal ganglion cell layer and the inner nuclear layer. SRGAP2 protein in the retina and optic nerve increased after optic nerve crush. Then, we established a heterozygous knockout (Srgap2+/-) mouse model of optic nerve crush and found that Srgap2 suppression increased retinal ganglion cell survival, lowered intraocular pressure, inhibited glial cell activation, and partially restored retinal function. In vitro experiments showed that Srgap2 suppression activated the mammalian target of rapamycin signaling pathway. RNA sequencing results showed that the expression of small heat shock protein genes (Cryaa, Cryba4, and Crygs) related to optic nerve injury were upregulated in the retina of Srgap2+/- mice. These results suggest that Srgap2 suppression reduced the robust activation of glial cells, activated the mammalian target of rapamycin signaling pathway related to nerve protein, increased the expression of small heat shock protein genes, inhibited the degeneration of retinal ganglion cells, and partially restored optic nerve function.

Analysis, environmental occurrence, fate and potential toxicity of tire wear compounds 6PPD and 6PPD-quinone.

Tire wear compounds N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and its derivative 6PPD-quinone have been considered as emerging pollutants and attracted much attention recently. As an antioxidant and antiozonant widely used, 6PPD would be released during the production or use of rubber-related products. Because of the mass production and wide use of rubber-related products, 6PPD and 6PPD-quinone have been identified to be ubiquitous in the environment. In this study, we firstly reviewed the current available literature on the analytical procedures, concentrations and distribution of 6PPD and 6PPD-quinone, and then investigated the potential toxic effects of these two compounds on aquatic organisms. Current studies have been mainly focused on the occurrence of 6PPD and 6PPD-quinone in dust and water, while available information on atmosphere, soil, sediments and organisms is limited. The fate and distribution of 6PPD and 6PPD-quinone would be influenced by environmental factors such as temperature, illumination, and storm events, etc. Although 6PPD and 6PPD-quinone have potential adverse effects on aquatic organisms, and 6PPD-quinone has species-specific toxicity, toxicological mechanisms of these compounds are still unclear. Based on the review and analysis of current studies, some suggestions for future research of 6PPD and 6PPD-quinone are given.

Circulating S100A8/A9 Levels Reflect Intraocular Inflammation in Uveitis Patients.

Purpose: To investigate whether there is an association between circulating S100A8/A9 levels and uveitis activity.Methods: A total of 549 plasma samples were collected from uveitis patients and non-uveitic controls.Results: S100A8/A9 plasma levels were elevated in uveitis patients compared to non-uveitic controls (P < 0.001). S100A8/A9 plasma levels in patients with active acute anterior uveitis (AAU) were significantly elevated and remarkably decreased in parallel with the severity of intraocular inflammation after corticosteroid treatment (P < 0.001). S100A8/A9 plasma levels were also higher in AAU patients with ankylosing spondylitis (AS) than in patients without AS (P = 0.02). S100A8/A9 plasma levels were significantly increased in uveitis patients with elevated C-reactive protein (CRP, P = 0.004) or erythrocyte sedimentation rates (ESR, P = 0.049) levels compared to uveitis patients with normal CRP or ESR values.Conclusion: Circulating S100A8/A9 might be a useful biomarker for the measurement of intraocular inflammation.

Elevated Plasma Levels of Drebrin in Glaucoma Patients With Neurodegeneration.

Glaucoma is an optic neuropathy characterized by progressive degeneration of retinal ganglion cells (RGCs). Aberrations in several cytoskeletal proteins, such as tau have been implicated in the pathogenesis of neurodegenerative diseases, could be initiating factors in glaucoma progression and occurring prior to axon degeneration. Developmentally regulated brain protein (Drebrin or DBN1) is an evolutionarily conserved actin-binding protein playing a prominent role in neurons and is implicated in neurodegenerative diseases. However, the relationship between circulating DBN1 levels and RGC degeneration in glaucoma patients remains unclear. In our preliminary study, we detected drebrin protein in the plasma of glaucoma patients using proteomic analysis. Subsequently, we recruited a total of 232 patients including primary angle-closure glaucoma (PACG), primary open-angle glaucoma (POAG) and Posner-Schlossman syndrome (PS) and measured its DBN1 plasma levels. We observed elevated DBN1 plasma levels in patients with primary glaucoma but not in patients with PS compared to nonaxonopathic controls. Interestingly, in contrast to tau plasma levels increased in all groups of patients, elevated drebrin plasma levels correlated with retinal nerve fiber layer defect (RNFLD) in glaucoma patients. To further explore the expression of DBN1 in neurodegeneration, we conducted experiment of optic nerve crush (ONC) models, and observed increased expression of DBN1 in the serum as well as in the retina and then decreased after ONC. This result reinforces the potentiality of circulating DBN1 levels are increased in glaucoma patients with neurodegeneration. Taken together, our findings suggest that circulating DBN1 levels correlated with RNFLD and may reflect the severity of RGCs injury in glaucoma patients. Combining measurement of circulating drebrin and tau levels may be a useful indicator for monitoring progression of neurodegenerative diseases.